The invention, in some embodiments, relates to the field of electric interconnect substrates and more particularly, but not exclusively, to electric interconnect substrates that in some embodiments are configured to support radiating electric components.
An interconnect substrate is a key element in the electronics industry. In a typical basic form, an interconnect substrate provides a platform for electro-mechanical attachment of electronic components. A plurality of electronic components, that are typically functionally associated together in one or more electric circuits, may be assembled and physically attached to such an interconnect substrate. The interconnect substrate provides the required electric interconnection between the components, as well as mechanical support that retains the mechanical integrity of the assembly. A well known example of such an interconnect substrate is a printed circuit board (PCB), to which electronic components may be attached by soldering.
In more advanced applications an interconnect substrate may provide, in addition to mechanical support and electric interconnect, also an effective means for removal of heat from the electric components attached thereon. Generally, heat removal from heat-generating electric components may be a considerable challenge in electronic circuitry design and employment. An interconnect substrate that comprises e.g. materials having high thermal conductance may provide solution to the challenge, by providing a channel for efficient heat removal, by facilitating heat flow from the heat generating electric components to the interconnect substrate, and further within the interconnect substrate itself. U.S. Pat. No. 6,670,704, US patent application 2010/0255274 and PCT patent application WO04049424 disclose a substrate interconnect comprising a valve metal such as aluminum, and an oxide of the valve metal, suitable, in some embodiments, for efficiently removing heat from heat generating components attached to the substrate interconnect. The valve metal in such substrate interconnects provides high thermal conductivity resulting in an efficient heat removal from hot regions, generally associated with heat sources such as heat-generating electric components, to cooler regions of the substrate. Segments of oxide of the substrate interconnect provides for electrical isolation, enabling distinct conductive channels which are electrically isolated from each other by the oxide segments.
Recent progress in the field of Light Emitting Diodes (LED's) is making high-power, high-efficiency light sources available for a large variety of usages. Hand-held flash-lights, interior saloon lighting and exterior lights for cars, and various lighting solutions for the home, have found in such high-power, high-efficiency LEDs an attractive solution. Yet, even with such recent progress in LEDs technology, a significant percentage—in some instance even above 50%—of the electric energy consumed by a LED device, is transformed into heat. Electronic components are generally adversely affected by high temperatures, and semiconductor junctions such that exist in LEDs might particularly suffer an increased likelihood of failure and shortening of operative life time with an increase of their operating temperatures. Thus, a substrate interconnect that can efficiently remove heat from heat-generating electric components, and particularly from LEDs assembled thereon, may be advantageous over other interconnects that remove heat less efficiently.
US patent application 2012/0112238 discloses a LED substrate and packaging for a single diode or a diode array. The substrate includes an integral reflector(s) for the diode(s) in the form of a shaped cavity (or cavities) to house the diode die(s). The reflector cavity walls can optionally be plated with a reflective material and may include a molding material to serve as lens and sealant. Also described is a method for building a substrate with direct metal connection of low thermal path between a die and a bottom surface of the substrate. Cavity formation is carried out by thinning the substrate in a desired region, in and around the region where a LED is to be installed, using techniques such as mechanical formation (drilling, punching, and the like), chemical etch formation or electro-chemical etching.